The 80 gallon Fresh water tank on my 1984 Classic Motorhome was MIA when I bought it, and replaced by a 15 gallon..
I have found a tank to replace it, but want the level system working too, and found this harness in the storage...

So I have following wires:
Black, Red, Green, Purple, and Orange with ring tabs.

Can anyone tell me how many sensor plugs I need(looks like 5) to get and how/where in the tank they need to go?
New tank is approx 14" tall.

I will try to scan the page tomorrow, but here are the connections according to the manual.
Water Tank Common Sensor= Red
Full Level Sensor= Orange
3/4 Sensor = Green
1/2 Sensor = Yellow
1/4 Sensor = Blue

The Black tank common Sensor wire color is Brown
The Gray tank common Sensor wire color is Gray
They all share the level sensor wires.

Awesome Rob!
You know, i feel silly now, as I have the service manual... and was looking for the wiring diagram for the tank... didnt think to look at the display panel diagram!
Doh!
So, to be clear..
I need a sensor very low in the tank.. and that is connected to red wire, and the rest in 1/4 tank height positions?

Well so much for the manual...typical.
Here is how it is really wired:
Purple to Full probe
Orange to 3/4 probe
Green to 1/2 probe
Red to 1/4 probe
Black to common probe
These wires come from the 6 way connector to the tank probes. The wires comming out of the wall going to the 6 way connector are different colors. They are together with the larger power and ground wires for the pump. They come out of the exterior wall basically below the filler tube.
The colors at the connector are as follows:
Blue with Yellow stripe = Purple
Orange/Yellow stripe = Orange
Green/Yellow stripe = Green
Red/Yellow stripe = Red
Black/Yellow stripe = Black
The following pictures should also help.
Rob